Steam safety-valve



(No Model.)

G. E. DIXON. STEAM SAFETY VALVE.

No. 393.748. Patented Dec. 4, 1888.

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UNITE STATES PATENT OFFICE.

GEORGE E. DIXON, OF CHICAGO, ILLINOIS.

STEAM SAFETY-VALVE.

SPECIFICATION forming part of Letters Patent No. 393,748, dated December 4, 1888.

Application filer". October 22, 1887. Serial No. 253,063- (No model.)

To all whom it may concern.-

Be it known that I, GEORGE E. DIXON, a subject of the Queen of Great Britain, a citizen of England, and a resident of Chicago, county of Cook, and State of Illinois, having declared my intention to become a citizen of the United States, have invented new and useful Improvements in Steam Safety-Valves, of which the following is a specification, reference being had to the accompanying drawings, illustrating the invention, in which Figure I is a vertical longitudinal sectional elevation taken centrally through the steam cushioned valve, and a vertical section on line X through the frame supporting the air-valve; Fig. II, a top view of all that portion which lies back of the section shown at Fig. I, and a full plan of the frame which supports the air-valve; Fig. III, a section of the dash-pot on line Z; Fig. IV, a plan of the steam-valve with top removed.

The purpose of this invention is so to construct a back-pressure valve that it may be connected with the exhaust-pipe of a steamengine, in order that the exhaust-steam may be utilized for heating apparatus. Should there be more exhaust-steam than is necessary to fill the apparatus, my back-pressure valve will operate automatically to discharge the same into the atmosphere. I attain, substantially, a noiseless valve device which will operate without a pounding movement and without the destruction of parts. I find in such valves that a very nice adjustment is required that the exhaust-steam may be utilized without interfering with the operation of the steam-boiler; and to this end I combine an air dash-pot to operate simultaneously with the steam-valve, especially when there is a surplus of exhaust-steam, whereby there can be no back action in the movement of the a mechanism.

lower annular seat, B, of the steam-valve,

and on the inner top part of the case over A is formed an inclined seat, 0, whereby when the valve is closed it has two seats. The

steam-valve consists of the inclined part D,

to be seated on the inclined part C, a vertical part, a, to fit the vertical part Eof the case, a horizontal part, F, to fit the seat B, a vertical part, (1, to fit the hole through the seat, and a top part, f, which is rigidly secured to a stem, G, whose lower portion has a proper guide in a bearing, T, secured to the lower part, A, of the case. This construction is such that steam coming in at pipe in excess of What is required to pass out at pipe Y will raise the valve F a cl f D and pass out of the case above, and the steam remaining between the seat B and valve part F will cushion the valve in its descent. To attain in addition the benefit of the air-cushioning of the dash-pot I J, a short lever, H, is affixed to a shaft, K, which extends into the case A A P V, and is supported by the part A. The inner end of the lever is slotted to engage the reduced portion of the valve-stem G, so that when the steam-valve is raised its stem will raise the inner end of the lever and turn the shaft K in its bearing in A. To the outer end of the shaft K is rigidly aflixed a long lever, L, by which, by means of a stem, m Z), the piston J in the dash-pot I will be elevated. This will cause the air to enter at the valve N and serve as an additional cushion to the steamvalve, so as to secure a delicate adjustment till it comes down to the position it is shown at Fig. I.

R is a petcock to regulate the escape of air, and M are weights to regulate the pressure of steam coming in at pipe The device is adapted to prevent excessive backpressure in exhauststeam pipes of engines, and constitutes what is known as a backpressure valve; but it is also adapted by suitable pipe-connections to control the escape of steam from various devices without noise, concussion, or abrasion of the working parts.

I claim as new- In automatic steam-valves, the case A A V P, open at its upper and lower ends and provided with the inclined seat C, horizontal seat B, in combination with a steam-valve consisting of the closed top part f, vertical parts a (1, level part F, and inclined part D to fit the seats of the case, and the stem and guide G T, as specified.

GEORGE E. DIXON.

*itnesses:

G. L. OHAPIN, ANNA D. J onnson. 

